Lopes Tina, Pinto Glória, Loureiro João, Costa Armando, Santos Conceição
Laboratory of Biotechnology and Cytomics, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
Tree Physiol. 2006 Sep;26(9):1145-52. doi: 10.1093/treephys/26.9.1145.
Microsatellites were used to test genetic stability in somatic embryos (SE) of Quercus suber L. The SE were obtained by a simple somatic embryogenesis protocol: leaf explants from two adult plants (QsG0, QsG5) and from two juvenile plants (QsGM1, QsGM2) were inoculated on Murashige and Skoog (MS) medium with 2,4-dichlorophenoxyacetic acid and zeatin. Calluses with primary embryogenic structures were transferred to MSWH (MS medium without growth regulators) and SE proliferated by secondary somatic embryogenesis. High morphological heterogeneity was found among cotyledonary SE. However, converted plants looked morphologically normal with well-developed rooting systems and shoots. The genetic stability of the plant material during the somatic embryogenesis process was evaluated by using six to eight nuclear microsatellites transferred from Q. myrsinifolia Blume, Q. petraea (Matts.) Liebl. and Q. robur L. Five of eight microsatellites distinguished among the genotypes analyzed, and for QsG0, QsGM1 and QsGM2, uniform microsatellite patterns were generally observed within and between SE and the respective donor genotypes. For genotype QsG5, the same pattern was observed in all samples analyzed except one, where the mutation percentage was 2.5%. We conclude that microsatellite markers can be used to assess genetic stability of clonal materials and to determine genetic stability throughout the process of somatic embryogenesis. The simple somatic embryogenesis protocol described has potential for the commercial propagation of Q. suber because it results in a low percentage of mutations.
利用微卫星标记检测软木栎体细胞胚的遗传稳定性。体细胞胚通过简单的体细胞胚胎发生方案获得：将来自两棵成年植株（QsG0、QsG5）和两棵幼年植株（QsGM1、QsGM2）的叶片外植体接种在添加了2,4-二氯苯氧乙酸和玉米素的Murashige和Skoog（MS）培养基上。具有初级胚性结构的愈伤组织转移至MSWH（无生长调节剂的MS培养基），体细胞胚通过次生体细胞胚胎发生进行增殖。在子叶体细胞胚中发现了高度的形态异质性。然而，转化植株在形态上看起来正常，根系和芽发育良好。利用从小叶青冈、欧洲栓皮栎和欧洲白栎转移而来的6至8个核微卫星标记，评估了体细胞胚胎发生过程中植物材料的遗传稳定性。8个微卫星标记中有5个在分析的基因型之间具有区分性，对于QsG0、QsGM1和QsGM2，在体细胞胚内部以及体细胞胚与各自供体基因型之间通常观察到一致的微卫星模式。对于基因型QsG5，除一个样本外，在所有分析样本中均观察到相同的模式，该样本的突变率为2.5%。我们得出结论，微卫星标记可用于评估克隆材料的遗传稳定性，并确定体细胞胚胎发生全过程的遗传稳定性。所描述的简单体细胞胚胎发生方案具有软木栎商业繁殖的潜力，因为其突变率较低。
